1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 *  linux/arch/arm/mach-omap1/ams-delta-fiq-handler.S
4 *
5 *  Based on  linux/arch/arm/lib/floppydma.S
6 *  Renamed and modified to work with 2.6 kernel by Matt Callow
7 *  Copyright (C) 1995, 1996 Russell King
8 *  Copyright (C) 2004 Pete Trapps
9 *  Copyright (C) 2006 Matt Callow
10 *  Copyright (C) 2010 Janusz Krzysztofik
11 */
12
13#include <linux/linkage.h>
14#include <linux/platform_data/ams-delta-fiq.h>
15#include <linux/platform_data/gpio-omap.h>
16
17#include <asm/assembler.h>
18
19#include "ams-delta-fiq.h"
20#include "board-ams-delta.h"
21#include "iomap.h"
22#include "soc.h"
23
24/*
25 * OMAP1510 GPIO related symbol copied from arch/arm/mach-omap1/gpio15xx.c.
26 * Unfortunately, it was not placed in a separate header file.
27 */
28#define OMAP1510_GPIO_BASE		0xFFFCE000
29
30/* GPIO register bitmasks */
31#define KEYBRD_DATA_MASK		(0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_DATA)
32#define KEYBRD_CLK_MASK			(0x1 << AMS_DELTA_GPIO_PIN_KEYBRD_CLK)
33#define MODEM_IRQ_MASK			(0x1 << AMS_DELTA_GPIO_PIN_MODEM_IRQ)
34#define HOOK_SWITCH_MASK		(0x1 << AMS_DELTA_GPIO_PIN_HOOK_SWITCH)
35#define OTHERS_MASK			(MODEM_IRQ_MASK | HOOK_SWITCH_MASK)
36
37/* IRQ handler register bitmasks */
38#define DEFERRED_FIQ_MASK		OMAP_IRQ_BIT(INT_DEFERRED_FIQ)
39#define GPIO_BANK1_MASK  		OMAP_IRQ_BIT(INT_GPIO_BANK1)
40
41/* Driver buffer byte offsets */
42#define BUF_MASK			(FIQ_MASK * 4)
43#define BUF_STATE			(FIQ_STATE * 4)
44#define BUF_KEYS_CNT			(FIQ_KEYS_CNT * 4)
45#define BUF_TAIL_OFFSET			(FIQ_TAIL_OFFSET * 4)
46#define BUF_HEAD_OFFSET			(FIQ_HEAD_OFFSET * 4)
47#define BUF_BUF_LEN			(FIQ_BUF_LEN * 4)
48#define BUF_KEY				(FIQ_KEY * 4)
49#define BUF_MISSED_KEYS			(FIQ_MISSED_KEYS * 4)
50#define BUF_BUFFER_START		(FIQ_BUFFER_START * 4)
51#define BUF_GPIO_INT_MASK		(FIQ_GPIO_INT_MASK * 4)
52#define BUF_KEYS_HICNT			(FIQ_KEYS_HICNT * 4)
53#define BUF_IRQ_PEND			(FIQ_IRQ_PEND * 4)
54#define BUF_SIR_CODE_L1			(FIQ_SIR_CODE_L1 * 4)
55#define BUF_SIR_CODE_L2			(IRQ_SIR_CODE_L2 * 4)
56#define BUF_CNT_INT_00			(FIQ_CNT_INT_00 * 4)
57#define BUF_CNT_INT_KEY			(FIQ_CNT_INT_KEY * 4)
58#define BUF_CNT_INT_MDM			(FIQ_CNT_INT_MDM * 4)
59#define BUF_CNT_INT_03			(FIQ_CNT_INT_03 * 4)
60#define BUF_CNT_INT_HSW			(FIQ_CNT_INT_HSW * 4)
61#define BUF_CNT_INT_05			(FIQ_CNT_INT_05 * 4)
62#define BUF_CNT_INT_06			(FIQ_CNT_INT_06 * 4)
63#define BUF_CNT_INT_07			(FIQ_CNT_INT_07 * 4)
64#define BUF_CNT_INT_08			(FIQ_CNT_INT_08 * 4)
65#define BUF_CNT_INT_09			(FIQ_CNT_INT_09 * 4)
66#define BUF_CNT_INT_10			(FIQ_CNT_INT_10 * 4)
67#define BUF_CNT_INT_11			(FIQ_CNT_INT_11 * 4)
68#define BUF_CNT_INT_12			(FIQ_CNT_INT_12 * 4)
69#define BUF_CNT_INT_13			(FIQ_CNT_INT_13 * 4)
70#define BUF_CNT_INT_14			(FIQ_CNT_INT_14 * 4)
71#define BUF_CNT_INT_15			(FIQ_CNT_INT_15 * 4)
72#define BUF_CIRC_BUFF			(FIQ_CIRC_BUFF * 4)
73
74
75/*
76 * Register usage
77 * r8  - temporary
78 * r9  - the driver buffer
79 * r10 - temporary
80 * r11 - interrupts mask
81 * r12 - base pointers
82 * r13 - interrupts status
83 */
84
85	.text
86
87	.global qwerty_fiqin_end
88
89ENTRY(qwerty_fiqin_start)
90	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
91	@ FIQ intrrupt handler
92	ldr r12, omap_ih1_base			@ set pointer to level1 handler
93
94	ldr r11, [r12, #IRQ_MIR_REG_OFFSET]	@ fetch interrupts mask
95
96	ldr r13, [r12, #IRQ_ITR_REG_OFFSET]	@ fetch interrupts status
97	bics r13, r13, r11			@ clear masked - any left?
98	beq exit				@ none - spurious FIQ? exit
99
100	ldr r10, [r12, #IRQ_SIR_FIQ_REG_OFFSET]	@ get requested interrupt number
101
102	mov r8, #2				@ reset FIQ agreement
103	str r8, [r12, #IRQ_CONTROL_REG_OFFSET]
104
105	cmp r10, #(INT_GPIO_BANK1 - NR_IRQS_LEGACY)	@ is it GPIO interrupt?
106	beq gpio				@ yes - process it
107
108	mov r8, #1
109	orr r8, r11, r8, lsl r10		@ mask spurious interrupt
110	str r8, [r12, #IRQ_MIR_REG_OFFSET]
111exit:
112	subs	pc, lr, #4			@ return from FIQ
113	@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
114
115
116	@@@@@@@@@@@@@@@@@@@@@@@@@@@
117gpio:	@ GPIO bank interrupt handler
118	ldr r12, omap1510_gpio_base		@ set base pointer to GPIO bank
119
120	ldr r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ fetch GPIO interrupts mask
121restart:
122	ldr r13, [r12, #OMAP1510_GPIO_INT_STATUS]	@ fetch status bits
123	bics r13, r13, r11			@ clear masked - any left?
124	beq exit				@ no - spurious interrupt? exit
125
126	orr r11, r11, r13			@ mask all requested interrupts
127	str r11, [r12, #OMAP1510_GPIO_INT_MASK]
128
129	ands r10, r13, #KEYBRD_CLK_MASK		@ extract keyboard status - set?
130	beq hksw				@ no - try next source
131
132
133	@@@@@@@@@@@@@@@@@@@@@@
134	@ Keyboard clock FIQ mode interrupt handler
135	@ r10 now contains KEYBRD_CLK_MASK, use it
136	str r10, [r12, #OMAP1510_GPIO_INT_STATUS]	@ ack the interrupt
137	bic r11, r11, r10				@ unmask it
138	str r11, [r12, #OMAP1510_GPIO_INT_MASK]
139
140	@ Process keyboard data
141	ldr r8, [r12, #OMAP1510_GPIO_DATA_INPUT]	@ fetch GPIO input
142
143	ldr r10, [r9, #BUF_STATE]		@ fetch kbd interface state
144	cmp r10, #0				@ are we expecting start bit?
145	bne data				@ no - go to data processing
146
147	ands r8, r8, #KEYBRD_DATA_MASK		@ check start bit - detected?
148	beq hksw				@ no - try next source
149
150	@ r8 contains KEYBRD_DATA_MASK, use it
151	str r8, [r9, #BUF_STATE]		@ enter data processing state
152	@ r10 already contains 0, reuse it
153	str r10, [r9, #BUF_KEY]			@ clear keycode
154	mov r10, #2				@ reset input bit mask
155	str r10, [r9, #BUF_MASK]
156
157	@ Mask other GPIO line interrupts till key done
158	str r11, [r9, #BUF_GPIO_INT_MASK]	@ save mask for later restore
159	mvn r11, #KEYBRD_CLK_MASK		@ prepare all except kbd mask
160	str r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ store into the mask register
161
162	b restart				@ restart
163
164data:	ldr r10, [r9, #BUF_MASK]		@ fetch current input bit mask
165
166	@ r8 still contains GPIO input bits
167	ands r8, r8, #KEYBRD_DATA_MASK		@ is keyboard data line low?
168	ldreq r8, [r9, #BUF_KEY]		@ yes - fetch collected so far,
169	orreq r8, r8, r10			@ set 1 at current mask position
170	streq r8, [r9, #BUF_KEY]		@ and save back
171
172	mov r10, r10, lsl #1			@ shift mask left
173	bics r10, r10, #0x800			@ have we got all the bits?
174	strne r10, [r9, #BUF_MASK]		@ not yet - store the mask
175	bne restart				@ and restart
176
177	@ r10 already contains 0, reuse it
178	str r10, [r9, #BUF_STATE]		@ reset state to start
179
180	@ Key done - restore interrupt mask
181	ldr r10, [r9, #BUF_GPIO_INT_MASK]	@ fetch saved mask
182	and r11, r11, r10			@ unmask all saved as unmasked
183	str r11, [r12, #OMAP1510_GPIO_INT_MASK]	@ restore into the mask register
184
185	@ Try appending the keycode to the circular buffer
186	ldr r10, [r9, #BUF_KEYS_CNT]		@ get saved keystrokes count
187	ldr r8, [r9, #BUF_BUF_LEN]		@ get buffer size
188	cmp r10, r8				@ is buffer full?
189	beq hksw				@ yes - key lost, next source
190
191	add r10, r10, #1			@ incremet keystrokes counter
192	str r10, [r9, #BUF_KEYS_CNT]
193
194	ldr r10, [r9, #BUF_TAIL_OFFSET]		@ get buffer tail offset
195	@ r8 already contains buffer size
196	cmp r10, r8				@ end of buffer?
197	moveq r10, #0				@ yes - rewind to buffer start
198
199	ldr r12, [r9, #BUF_BUFFER_START]	@ get buffer start address
200	add r12, r12, r10, LSL #2		@ calculate buffer tail address
201	ldr r8, [r9, #BUF_KEY]			@ get last keycode
202	str r8, [r12]				@ append it to the buffer tail
203
204	add r10, r10, #1			@ increment buffer tail offset
205	str r10, [r9, #BUF_TAIL_OFFSET]
206
207	ldr r10, [r9, #BUF_CNT_INT_KEY]		@ increment interrupts counter
208	add r10, r10, #1
209	str r10, [r9, #BUF_CNT_INT_KEY]
210	@@@@@@@@@@@@@@@@@@@@@@@@
211
212
213hksw:	@Is hook switch interrupt requested?
214	tst r13, #HOOK_SWITCH_MASK 		@ is hook switch status bit set?
215	beq mdm					@ no - try next source
216
217
218	@@@@@@@@@@@@@@@@@@@@@@@@
219	@ Hook switch interrupt FIQ mode simple handler
220
221	@ Don't toggle active edge, the switch always bounces
222
223	@ Increment hook switch interrupt counter
224	ldr r10, [r9, #BUF_CNT_INT_HSW]
225	add r10, r10, #1
226	str r10, [r9, #BUF_CNT_INT_HSW]
227	@@@@@@@@@@@@@@@@@@@@@@@@
228
229
230mdm:	@Is it a modem interrupt?
231	tst r13, #MODEM_IRQ_MASK 		@ is modem status bit set?
232	beq irq					@ no - check for next interrupt
233
234
235	@@@@@@@@@@@@@@@@@@@@@@@@
236	@ Modem FIQ mode interrupt handler stub
237
238	@ Increment modem interrupt counter
239	ldr r10, [r9, #BUF_CNT_INT_MDM]
240	add r10, r10, #1
241	str r10, [r9, #BUF_CNT_INT_MDM]
242	@@@@@@@@@@@@@@@@@@@@@@@@
243
244
245irq:	@ Place deferred_fiq interrupt request
246	ldr r12, deferred_fiq_ih_base		@ set pointer to IRQ handler
247	mov r10, #DEFERRED_FIQ_MASK		@ set deferred_fiq bit
248	str r10, [r12, #IRQ_ISR_REG_OFFSET] 	@ place it in the ISR register
249
250	ldr r12, omap1510_gpio_base		@ set pointer back to GPIO bank
251	b restart				@ check for next GPIO interrupt
252	@@@@@@@@@@@@@@@@@@@@@@@@@@@
253
254
255/*
256 * Virtual addresses for IO
257 */
258omap_ih1_base:
259	.word OMAP1_IO_ADDRESS(OMAP_IH1_BASE)
260deferred_fiq_ih_base:
261	.word OMAP1_IO_ADDRESS(DEFERRED_FIQ_IH_BASE)
262omap1510_gpio_base:
263	.word OMAP1_IO_ADDRESS(OMAP1510_GPIO_BASE)
264qwerty_fiqin_end:
265
266/*
267 * Check the size of the FIQ,
268 * it cannot go beyond 0xffff0200, and is copied to 0xffff001c
269 */
270.if (qwerty_fiqin_end - qwerty_fiqin_start) > (0x200 - 0x1c)
271	.err
272.endif
273